1. The Field of the Invention
This invention relates to computerized graphic systems and, more particularly, to a novel system and method of computerized graphics in which a relatively small number of control data points generated by a parametric function are rapidly processed using a novel data processing pipeline so as to generate real time animation of graphical illustrations, even though such illustrations may be composed of curved lines or curved surfaces.
2. The Prior Art
During recent years, there has been an increased interest in the technology of computer graphics and computer-aided animation. It has been found that such technology can significantly reduce costs and increase productivity in a number of different fields.
Television broadcasters, for example, are often in need of graphic designs for use in their broadcasts. This is particularly true in the case of news broadcasts, where maps and graphs are frequently desired in order to help explain newsworthy events. Moreover, in many instances, it is also desirable to animate such graphic designs and illustrations during the broadcast. Using traditional illustration and animation methods, however, it would usually take several hours to produce the desired, animated result. Therefore, broadcasters have begun to routinely rely upon various computer-aided illustration and animation systems in order to meet their stringent time deadlines.
Another area in which computer-aided graphic design and animation has been increasingly employed, is that of computer-aided design. A growing number of manufacturers are finding that the graphic capabilities available through various computer graphic systems can greatly increase manufacturing productivity and significantly reduce design costs.
As a result of this growing interest in and need for computer graphics and computer-aided animation systems, a number of such systems have been developed which seek to meet the needs of various users. Typically, in such systems, an illustration is first converted into a number of data points. Importantly, it is desirable to obtain enough data points such that curved lines in the illustration will look smooth when adjacent data points are connected by a small line segment. It will be appreciated, therefore, that curved portions of an illustration will usually contain a significant number of data points. Once obtained, the numerous data points are then stored in some type of a memory device within the system.
Next, a viewing field is selected. The data points are then processed by the system in order to determine which points lie inside of the viewing field. Data points which lie outside the viewing field are then eliminated, and the illustration is thus "clipped" to the viewing field. After this "clipping" is completed, adjacent data points are connected by a short line segment so as to define some type of closed, graphic figure. Thereafter, each such graphic figure is typically colored or shaded in response to commands from the system user. The numerous colored figures are then displayed on a video monitor or other output device so as to produce the desired graphical illustration.
Although the prior art systems have greatly facilitated the preparation of graphic designs and animation, such systems also have a number of drawbacks and disadvantages, especially in terms of the ability of such systems to efficiently animate illustrations which have curved lines and surfaces. Most prior art systems will define each curved line in an illustration in terms of a relatively large number of data points which are then connected by line segments so that the line segments collectively approximate the curved line. If it is desired to modify the illustration in order to create animation, each of the data points for each line segment must be re-processed. For example, if the letter "S" were to be enlarged or rotated about an axis, the numerous data points used to approximate the curves of the "S" would each be processed a number of successive times. The large number of data points which must be processed greatly increases the storage capacity required for the system, as well as the processing time which is required.
Further, as mentioned above, the data points which are used to define the curved lines used in an illustration are connected by a series of short line segments which approximates the curved lines of the illustration. It will be appreciated, therefore, that when the illustration is enlarged on the viewing screen, the individual line segments become more visible, thus rendering the illustration less smooth. An analogous problem exists when attempting to approximate a curved surface. The prior art systems have not yet devised a way to overcome this problem, except through the use of complex shading techniques.
Still further, it has been found that the prior art systems are generally incapable of producing both line drawings and solid figures. Thus, a prior art system will typically produce either solid figures or line drawings, but such systems can rarely produce both kinds of drawings. Moreover, even if a prior art system can produce both solid figures and line drawings, prior art systems are generally incapable of incorporating both kinds of drawings into the same illustration.
Accordingly, it would be an improvement in the art to provide a system and method for generating and animating graphical illustrations which minimizes the number of data points which must be stored and processed. It would also be an improvement in the art to provide a system and method for processing data points representing graphical illustrations which minimizes the time required for processing such data points. Additionally, it would be an improvement in the art to provide a system and method for generating graphical illustrations wherein the illustrations remain smooth even after enlargement. Further, it would be an improvement in the art to provide a system and method for generating graphical illustrations which is capable of rendering both solid figures and line drawings within the same illustration. Such a system and method is disclosed and claimed herein.